Sinopec's Addax Petroleum said on Thursday it had successfully concluded negotiations with Gabon over a disputed oil licence and signed a new contract for three oil fields.

Gabon transferred the Obangue oil field from Addax to the state oil firm more than a year ago, citing breach of contract, in a move that sparked a $1 billion legal battle in a Paris-based tribunal.

The decision ends a case closely watched by investors as Gabon tries to lure investment as part of an effort to double oil production to 500,000 barrels per day.

"I am pleased to confirm that our efforts to resolve amicably all existing issues and disputes have borne fruit and resulted in the completion of our negotiations with the Gabonese government," said Yi Zhang, chief executive of Addax Petroleum, in an emailed statement.

It was not immediately possible to confirm the decision with Gabon's oil ministry, although a source close to the matter also confirmed that an agreement had been reached.

Geneva-based Addax accounts for about a third of top Chinese refiner Sinopec's overseas oil production. The new production sharing contract is for the Obangue, Tsiengui and Autour fields in which Addax had previously held an interest.